Suricata is a network Intrusion Detection System, Intrusion Prevention System and Network Security Monitoring engine. Prior to versions 6.0.16 and 7.0.3, an attacker can craft traffic to cause Suricata to use far more CPU and memory for processing the traffic than needed, which can lead to extreme slow downs and denial of service. This vulnerability is patched in 6.0.16 or 7.0.3. Workarounds include disabling the affected protocol app-layer parser in the yaml and reducing the stream.reassembly.depth
value helps reduce the severity of the issue.